Optus joins Voice over LTE race

Optus has tested out technology to let its customers make voice calls over its 4G long-term evolution (LTE) network instead of the existing 2G and 3G networks.

LTE networks in Australia today from Optus, Telstra, and Vodafone exist as pure data networks that rely on the telcos' existing 2G and 3G networks for customers with 4G handsets to make voice calls. Given most customers are still using 3G devices, there is no rush for the telcos to move voice calls onto 4G and begin decommissioning the 3G and 2G networks.

Last week ZDNet revealed that Telstra was already testing out VoLTE (Voice over LTE) in its lab, with a view to launch the service in 2014. Optus' new managing director of networks, Vic Mcclelland told ZDNet that Optus too is also working on VoLTE.

"Optus follows all mobile network technology developments closely," he said in a statement.

"We have been carrying out trials for both HD Voice and VoLTE, and we are examining the benefits these technologies can potentially deliver to our customers."

ZDNet understands that some of the trials were conducted with Nokia Siemens Networks, Optus' 4G network vendor partner.

Telstra has had HD voice services since 2011. Vodafone confirmed last week that it has not yet tested out VoLTE technology, but has implemented HD voice.